Electrical: Help, advice, wiring question

[Edsel G. Tattooer]

So I have a 51 land cruiser 33k original miles. THe problem is it has been molested by a (expletive deleted) mechanic.

Someone put an after market "Haywire kit" wired it neg ground. So after I tring to get things to work like the turn signals and lights and brake lights. I found they cut the wires to the brake lights. and in the process cut the over drive wires also.

Im at the point rather than repair all the wiring run new runs to tail lights and transmission. Im thinking or just buying a factory set of wires and replacing any of the breakers they might have tossed out.

also after I get it all working then I have to clean up the rats nest of to short and to long wires every where.

What would you do?

Also Who sells a non cloth covered harness that is labeled for where they get attached.

[rockne10]

Lark Works can make the '51 harness in either the original braided wire or in the cheaper vinyl coated wire. And everything will be correct, and with coded ends.
If it's still 6-volt it needs the heavier gauge wire that was standard in '51

[wdills]

Based on what you are describing, I would rip out everything that is currently in the car and buy a new harness. The new harness will be made for 6V pos ground. If you want to keep it 12V neg ground, then modify there new harness as necessary. Much easier to work with a fresh factory harness that it is to try to figure out what someone else did and didn't document.

If you decide to modify your new wiring harness for 12V, I would suggest getting a wiring diagram printed out on large paper like 22" x 34". Then as you make changes to the cars wiring, modify the wiring diagram to match. Then when you are done, you will have a wiring diagram for that car that you or others can use in the future to troubleshoot problems. I created one of these when I built my car. I keep it in the car all the time, just in case I need it.

Good luck
Wayne

[Edsel G. Tattooer]

I was thinking of restore but 12v positive ground.
I know I was thinking like other great minds!


Thanks for the input.
Any other advise?

[sweetolbob]

If you are planning to go to 12v neg and tearing out everything, you might consider an aftermarket harness. Speedway has a 12 fused circuit universal harness for $149 and 21 fused for $189. I'm not trying to talk you out of using a vendor but if you are comfortable with wiring and have more time than money, it's an option.

https://www.speedwaymotors.com/Speedway-Motors-Universal-12-Circuit-Mini-Fuse-Wiring-Harness,2352.html

Bob

[RadioRoy]

The wiring is the same from 6 volt positive ground to 12 volt negative ground. The only difference MIGHT be around the generator/voltage regulator, if the car has been changed to an alternator. The only other difference is the ammeter terminals get swapped. An alternator cares about polarity, but none of the old electrics care about polarity, after the generator is polarized. None of the switches get changed.

If the car is already 12 volts, then it will be easier to leave it 12 volts, negative ground. Do not switch it to 12 volts positive ground. That is a completely weird, uncommonly used configuration. Some English cars used that, but it's not a good idea to use an English car as an example to follow.


Studebakers West makes correct wiring harnesses with plastic insulation and the correct colors and wire sizes.


Read all you can on the subject and educate yourself.

[kurtruk]

Roy,
Are you sure Studebakers West labels their harnesses? Last ones (many years ago) I got were not labeled. I spent a few afternoons with a wiring diagram and adhesive labels sorting it all out.

[StudeRich]

No, it should not be necessary to "Label" wires in a Factory Correct Harness, and they do not.

You do as others have said, and enlarge a '51 Commander Wiring Diagram and connect the Color Codes and Wire Gauge correctly.
Most wires fall into place due to their correct length, especially under the Hood.

[Skip Lackie]

I was thinking of restore but 12v positive ground.
I know I was thinking like other great minds!


Thanks for the input.
Any other advise?

I would not try to go with 12v positive ground, a system almost no one (Packard for one year?) ever used. If the vehicle is 12 volts, everyone will assume it's negative ground.

[jclary]

Personally, I prefer the wiring size of the six volt systems. I am open to being educated if someone can provide me with a good reason to think otherwise. But, it is my understanding that six volt systems required (in general) bigger wire gauges due to six volt systems push a larger current draw at the lower voltage. (One of those electrical concepts that seem to flop between science and mythical magic to those of us who only tinker with it occasionally). It is also my understanding that as automobiles became more complex, adding as standard equipment stuff like extra lights, radios, heat & air fan motors, electrical demands required more capacity than could be crammed into a six volt demand.

Here in the USA, it seems like within a two year period, 1955-56, the entire industry changed to 12 volt systems. Even though I have had some training, I don't daily live in the electrical repair/service profession, and thus my aging mind requires frequent refreshing by way of keeping manuals close by. That said...I would always want to keep my 6 volt vehicles wired by the schematic standards with which they were originally designed. Even if I chose to convert to a 12 volt system, my only change would be to go negative ground, and do my best to improve the fuse protection of each circuit. The beauty of keeping the heavier gauge 6 volt wiring system is that the vehicle could always be returned to originality without having to rewire everything.

In fewer words, you can safely use 12 volts with a six volt wiring harness, but not the reverse. Make certain to replace the crappy original six volt crumbling insulated wire that would flake away and expose bare wire to shorting to ground.

If I'm wrong...educate me.

[RadioRoy]

Roy,
Are you sure Studebakers West labels their harnesses? Last ones (many years ago) I got were not labeled. I spent a few afternoons with a wiring diagram and adhesive labels sorting it all out.

Kurtruk, You are probably right. What I meant to write was that the colors matched the colors on the wiring diagram. Sorry for any confusion created and I edited my post.

Jclary, I agree entirely with your post as well.

I agree entirely with Skip's and Rich's posts also.

[Edsel G. Tattooer]

Ok so now that many have said their piece I will make the car 12 neg with a 6volt wire harness. Is there any thing I can do about keeping the Stock radio working it's the only thing I cant think of that wont work with neg ground by reversing the wires or a 12v to 6v dropping resister.

Thanks for all the input! its the reason I love this forum.

Edsel

[StudeRich]

The Fuel and Temp. Gauges will need the 12 to 6 Volt-A-Drop, and there "Used to be" 6 Positive" to 12 Negative ground higher output Radio converters, probably requiring Insulating the Radio from ground?
I am sure Radio Roy would know how you do that.

[RadioRoy]

The radio is not polarity sensitive if it still has the original mechanical vibrator. The new solid state vibrators ARE polarity sensitive, but are available in negative ground. The rest of the radio is just fine with either polarity.

The challenge is dropping the voltage at the radio's 9 amp or so power draw.

J.C. Whitney used to sell dropping resistors for the radio, but they got hot and did not work exceptionally well.

It is not easy to convert the original technology radio to 12 volts. It requires a new power transformer and a certain amount of tube substitution, or wiring like tube filaments in series.

There is a new solid state dropping converter on the market that works somewhat well, does not get hot, and is inexpensive (~$40). Unfortunately, the Chinese engineers who developed it designed it to put out exactly 6 volts, when actual operation of a "6 volt" car radio is closer to 6.7 volts. What were they thinking?

An Aurora Design AM/FM conversion will give the radio a new life. Just ask Matthew and some other folks on this forum how they like theirs. But it is not cheap.

http://www.tech-retro.com/Aurora_Design/Home.html

[RadioRoy]

I just checked eBay. There are fewer 12-6 volt reducers than there used to be and they are closer to $40. Maybe folks didn't like them.

https://www.ebay.com/itm/223420425030?format=1&hlpv=1&cond=1